1. Field of the Invention
The present invention relates to a photodiode array.
2. Related Background of the Invention
A multichannel photodiode and a photodiode array have been known as a photodetecting element having a plurality of pixel regions formed on the same substrate. The greatest problem of the multichannel photodiode and photodiode array is cross talk between pixels.
As a method for preventing cross talk between the pixels, for embodiment, a structure where trench grooves are formed between the pixels and the trench grooves are filled with an insulating material to maintain the mechanical strength is disclosed in Japanese Patent Laid-Open Publication No. 2001-352094. FIG. 13 is a sectional view showing a photodiode array disclosed in Japanese Patent Laid-Open Publication No. 2001-352094. With reference to FIG. 13, a photodiode array 100 is provided with a plurality of photodiodes 101. The photodiode 101 consists of an n-type semiconductor layer 102 and a p-type semiconductor layer 103. An element isolating trench groove 104 is formed between the plurality of photodiodes 101, and the surface of the trench groove 104 is covered with an insulating layer 105. The trench groove 104 is filled with a filling material 106.
However, since three steps (a step of forming the trench groove 104, a step of forming the insulating layer 105 on the surface of the trench groove 104, and a step of filling the trench groove 104) are required in the case of the above-mentioned photodiode array 100, working hours according to these steps are required. Though it is also considered that the step of filling the trench groove 104 is omitted, the mechanical strength of the photodiode array 100 is reduced.